This project seeks to determine the impact of conditions in a laminar diffusion flame on the formation of metallic aerosols. The flame parameters include temperature and metals loading. Chlorinated species will be added to the flames to evaluate the impact of chlorine on the aerosol formation. Interactions between metals and chlorine that lead to hazardous by-products shall be examined. Samples of the metal aerosols and of the gas phase species shall be analyzed with bio-marker techniques to evaluate the toxicity of these combustion by-products.